1. Field of the Invention
The invention relates to an apparatus for determining the time-of-flight mass analysis of energetic atomic particles, such as ions or electrons, and more particularly, to an apparatus that, in addition to determining a precise time information, determines the positions of individual atomic particles.
2. Description of the Related Art
A number of devices have been utilized for measuring the masses of atoms, molecules, and molecular fragments. Among the most accurate devices for such measurements is the "time-of-flight" mass spectrometer, which measures the time required for positive ions to reach an ion detector. At equal energies, lighter ions travel through the spectrometer more quickly reaching the ion detector before heavier ions. The ion detector is connected to a device that measures the number of ions reaching the detector in a given time interval as well as the relative number of atoms as a function of the mass number.
Several disadvantages exist in prior art devices. The most severe of such disadvantages are insufficient timing accuracies and limited count rates. Furthermore, most ion detectors are not position sensitive. In the present invention, these shortcomings are eliminated by a a special waveguide or waveguide-like designs. The resulting timing accuracy and count rate are extremely accurate. In addition to the improved timing properties, the invention simultaneously achieves position information. This information can be used to determine the position of an individual atomic particle and/or allow the timing signal to correct slightly for each position on the detector surface. Therefore the present invention exhibits a significant improvement over prior art time-of-flight mass spectrometers.
For the foregoing reasons, there is a need for a fast timing position sensitive detector for determining the time-of-flight mass of atomic particles that includes multi-anode collectors located between the channel plates and the backplate or ion detector.